Hey Tami - I've used this lens before.
It is really nice, sharp and has really great close focusing.
Filters (if you use them) can only be used in the back of the lens.
Here is a link to the last images I shot with it.(I sold off my Canon gear to go back to Nikon)
Mouse over any image and the exif data will pop in from the left side.
You can pretty much tell which images I used the 14mm on.
I was also using my 5D - so the perspective is wonderful on a FF.
Feel free to ask me anything further.